Figure 19 in Spatio-Temporal Variability of Algal Bloom in the Caspian Sea

Figure 19 shows interannual variability of monthly averaged wind speed for June, July, August and September in 2000-2022. We can see that all bloom events occurred when monthly averaged wind speed was in the range of 4.3-5.0 m/s. In general, low wind speed should be favorable for algal bloom due to absence of wind-wave mixing, but the problem is that this area of the Caspian is the calmest area of the sea (Rahimi et al. 2022). Only twice, in September 2016 and 2019, wind speed reached 5.5-5.75 m/s (Figure 19). Seemingly, every year should be favorable for algal bloom, but that is not true. Moreover, in August 2003, 2006, 2007, 2014, and 2016, wind speed was less than 4.3 m/s and no algal blooms were recorded in these years.